1. Field of the Invention
The present invention relates to an apparatus for brewing infusible plant substances, especially tea.
With the exception of water, tea is the most widely consumed of all beverages. Its world-wide per capita consumption has been estimated at 0.1 litre per day. In western countries tea tends to be brewed at home, however, there is a growing trend for consumers to consume tea out of home in cafes and bars. It is thought that consumers prefer to enjoy a tea experience that involves more than being supplied with a tea bag and hot water. There is therefore a need for an alternative brewing method.
Coffee brewing equipment is a familiar feature of cafes and bars. Tea is however much more sensitive to brewing than coffee. Extended steeping in water often ruins the beverage. Too short a steeping time results in too diluted a drink.
2. Description of Related Art including Information Disclosed under 37 CFR 1.97 and 1.98
Commercial tea brewing machines are known too. For examole European patent specification EP 898917 (Unilever) discloses an apparatus for brewing tea that has a housing with a water inlet channel, a heater to heat the water delivered through the channel and a water dispenser within the housing for providing a spray of hot water to a brewing pot. The housing includes a filter receotacle that can contain a filter basket of wire mesh or fluted filter paper. The apparatus has a siphoning mechanism that has been constructed so that the function of the apparatus is unimpaired by tea particle interference in the brewing mechanism. The apparatus is designed to allow for tea to steep in its optimal range of from 3 to 5 minutes. The showering action is central to achieving that.
Such an apparatus has proved successful in preparing batches of freshly brewed hot tea however it is not suited to providing individual servings in quick succession as is required in a busy tea shop. When the filter basket is made of wire mesh it can be difficult to quickly clean it thoroughly enough between brews. When the filter basket is made of fluted filter paper it can become costly to replace it each time, time consuming tho fit and fill it, and inconvenient to dispose a large number of them.
United Kingdom patent specification GB 2184644 (W. M. Still & Sons) similarly discloses a tea making apparatus that involves showering hot water over a bed of leaves. Means are provided for delaying the passage of the heated water through the tea leaves to allow for a good extraction. Once that is achieved the tea is dispensed by a siphoning action. U.S. Pat. No. 4,527,467 (Phillios) discloses another filter device. Tea leaves placed in a bowl having an outlet aperture formed in its bottom for discharge of brewed tea. An outlet tube communicates with the outlet aperture and extends upwardly from the bottom of the bowl. A sleeve surrounds the outlet tube with a space between them providing an annular siphon passageway. The upper end of the sleeve is closed while the lower end rests on the bowl bottom. Capillary inlet apertures are formed in the lower portion of the sleeve. As the liquid therefore falls in the bowl, the static pressure of the liquid retained in the annular siphon passageway is balanced by the capillary pressure of the retained liquid and the capillary inlet apertures. Passage of airway bubbles through the capillary inlet apertures is thereby prevented. Upon addition of further liquid to the bowl, the siphoning operation immediately resumes.
While the siphon arrangement in U.S. Pat. No. 4,527,467 advanced the art, it is still subject to certain problems. Tea placed within the bowl for brewing can migrate to the capillary. Particles of tea can then preclude the capillary inlet apertures and interfere with siphoning. Sometimes relatively small particles can be slipped through the capillary inlets with eventual siphoning into the consumer's brew. These particles in the brewing product are aesthetically and tastewise very undesirable.
Accordingly, it is an object of the present invention to provide a tea brewing apparatus that is suitable for providing individual servings of high quality freshly brewed tea in a busy shop situation.
It is an alternative and more general object of the present invention to provide a brewing machine suitable for brewing tea that is at least a useful alternative to those currently available.